Fan arrangement

ABSTRACT

A fan arrangement ( 10 ) has a first axial fan ( 20 ), a second axial fan ( 40 ), and a guide apparatus ( 60 ). The first axial fan has: a first electric motor ( 21 ) having a first external rotor ( 22 ) and a first internal stator ( 23 ); a first fan wheel ( 24 ) connected to the first external rotor and having a first plurality of fan blades ( 25 ); a first base part ( 26 ) connected to the first internal stator; and a first fan housing ( 27 ) that at least partly surrounds the first electric motor. The second axial fan has: a similar structure. The first fan housing defines, together with the first fan wheel, an annular first conduit ( 32 ) through which a fluid is deliverable during operation by rotation of the first fan wheel around a first rotation axis ( 30 ) of the first external rotor. The second fan housing defines, together with the second fan wheel, an annular second conduit ( 52 ) through which the fluid is deliverable, during operation, by rotation of the second fan wheel around a second rotation axis ( 50 ) of the second external rotor.

CROSS-REFERENCES

This application is a section 371 of PCT/EP2015/059963, filed 2015 May 6, published 2015 Dec. 10 as WO-2015-185314-A, and further claims priority from our application DE 10 2014 108 073.4, filed 2014 Jun. 6, the entire content of which is incorporated by reference.

FIELD OF THE INVENTION

The invention relates to a fan arrangement having a first axial fan, a second axial fan, and a guide apparatus.

BACKGROUND

In fan arrangements, it can be necessary to couple a plurality of fans in order to achieve a necessary air output. The fans can be combined with one or more guide apparatuses, and the guide apparatuses can also be implemented as diffusers. Different combinations result depending on the requirement.

The guide apparatuses can be configured in such a way that a swirl is removed from or impressed upon a flow of a fluid delivered by the fan arrangement. The overall output of the fan arrangement can thereby be increased. It is also possible for the guide apparatuses to have only a structural function.

SUMMARY OF THE INVENTION

The object of the present invention is to furnish a novel fan arrangement.

According to an embodiment, in order to achieve the object the fan arrangement comprises a first axial fan, a second axial fan, and a guide apparatus. The first axial fan comprises: a first electric motor having a first external rotor and a first internal stator; a first fan wheel connected to the first external rotor and having a first plurality of blades; a first base part connected to the first internal stator; and a first fan housing that at least partly surrounds the first electric motor. The second axial fan comprises: a second electric motor having a second external rotor and a second internal stator; a second fan wheel connected to the second external rotor and having a second plurality of fan blades; a second base part connected to the second internal stator; and a second fan housing that at least partly surrounds the second electric motor. The first fan housing defines, together with the first fan wheel, an annular first conduit through which a fluid is deliverable during operation by rotation of the first fan wheel around a first rotation axis of the first external rotor. The second fan housing defines, together with the second fan wheel, an annular second conduit through which the fluid is deliverable during operation by rotation of the second fan wheel around a second rotation axis of the second external rotor.

The guide apparatus comprises a guide apparatus housing and a guide apparatus inner part connected to the guide apparatus housing with the aid of webs, which guide apparatus housing defines, together with the guide apparatus inner part, an annular third conduit through which the fluid is deliverable.

The first base part is attached to a first portion of the guide apparatus inner part and the second base part is attached to a second portion of the guide apparatus inner part; the first axial fan, the second axial fan, and the guide apparatus are connected to one another in such a way that the first annular conduit, the second annular conduit, and the third annular conduit form a flowthrough-capable air conduit of the fan arrangement.

The advantage is that the first axial fan and the second axial fan are connected with the aid of the guide apparatus, the guide apparatus performing a function of bracing and thus supporting the two axial fans. With the aid of this fan arrangement it is possible in simple fashion to furnish a combination of axial fans and at least one guide apparatus. An aerodynamic straightening function, or conditioning of the fluid, is thus integrated into the fan arrangement. It is likewise possible to implement the guide apparatus as a protective grid, in particular when the guide apparatus is mounted on an inflow surface of the fan arrangement and/or on an outflow surface of the fan arrangement.

The fan arrangement achieves a modular construction for a single- or multi-stage axial fan. The modules (axial fan(s) and guide apparatus) can be adapted to the intended purpose and can be combined

into a fan arrangement using standardized connecting elements, for example screws, bolts, or clips, or with the aid of adhesive joins or press-fits.

A modular principle of this kind makes it possible to combine several fans, which are implemented both identically and differently from one another, in order to obtain a corresponding change in a fan characteristic curve. All combinations, in terms of number of axial fans and guide apparatuses, rotation speed of the axial fans, and shapes, are conceivable.

A further advantage is also simple installation and removal of the axial fans and guide apparatuses, yielding a cost reduction in the context of both manufacture and maintenance operations.

In an embodiment of the fan arrangement, a longitudinal axis of the guide apparatus, the first rotation axis, and the second rotation axis are implemented coaxially in order to achieve simple planar, and thus sealing, contact planes between the individual modules.

In a further embodiment of the fan arrangement the guide apparatus inner part comprises, for further conditioning of the fluid, guide vanes on a lateral surface implemented to face toward the guide apparatus housing. Especially when a combination of movable guide vanes and webs, connected to the guide apparatus housing, is implemented on the guide apparatus inner part, a conditioning of the fluid during operation of the fan arrangement which is adapted to a corresponding throughput volume of fluid is achievable in simple fashion. Particularly stable grouping of the modules of the fan arrangement is achievable by the fact that the guide apparatus is connected immovably to the first internal stator and/or to the second internal stator, since the internal stator, because of its longitudinal dimension extending over almost the entire axial fan, is a stable element of the axial fan, i.e. one suitable for a supporting function.

In an advantageous embodiment of the fan arrangement, in order to achieve a compact arrangement of the axial fans and of the guide apparatus, the first base part is implemented to position the first internal stator and a first bearing arrangement for a first shaft of the first electric motor, and/or the second base part is implemented to position the second internal stator and a second bearing arrangement for a second shaft of the second electric motor.

Simple bracing in an axial direction is achieved by the fact that the first base part abuts in an axial direction against the first portion, and/or that the second base part abuts in an axial direction against the second portion.

A disk-shaped region, particularly preferably in the shape of a disk-shaped partition, is preferably implemented on the guide apparatus inner part, which region serves as an axial stop at least for the first base part so that tilting or jamming of the first base part is avoidable.

Advantageous radial bracing results from abutment of the first base part in a radial direction against the first portion, and/or of the second base part in a radial direction against the second portion.

For further stable bracing of the modules, the first fan housing and/or the second fan housing are immovably connected to the guide apparatus housing. Targeted bracing of the axial fans is thus brought about not exclusively with the aid of the base parts and the guide apparatus inner part, but instead bracing is further ensured by connecting the housings of the individual modules in order to achieve a stable fan arrangement.

In a further embodiment of the fan arrangement the first base part and/or the second base part are inexpensively connected to the first portion and/or to the second portion in the form of a press fit.

In addition to the capability of conditioning the fluid with the aid of the guide apparatus, further conditioning of the fluid is achievable with the aid of the air conduit implemented in the manner of a Venturi tube. For example, a fluid velocity in an entrance region of the fan arrangement can be increased if the air conduit comprises

a constriction, proceeding from an entrance surface of the air conduit. The fluid velocity can likewise be reduced in an exit region of the fan arrangement if a constriction of the air conduit in the direction of an exit surface of the air conduit is brought about by implementing the air conduit in the manner of a Venturi tube.

A third axial fan, which is connected via a further guide apparatus to the first fan or to the second fan, is preferably provided.

A fourth axial fan, which is connected via a further guide apparatus to the third axial fan, is preferably provided.

The capability of coupling any number of fans to one another using the guide apparatus permits a modular structure for the fan arrangement, in which a fan arrangement adapted to the aerodynamic requirements can be constructed using a small number of different components.

Further advantages, features, and details of the invention are evident from the description below of preferred exemplifying embodiments, and with reference to the drawings. The features and feature combinations recited above in the description, as well as the features and feature combinations recited in the description and the features and feature combinations recited below in the description of the Figures and/or only shown in the Figures, are usable not only in the respective combination indicated but also in other combinations or in isolation without departing from the context of the invention. Identical or functionally identical elements have identical reference characters associated with them. For reasons of clarity, it is possible that the elements are not labeled with their reference characters in all the Figures, although they do not lose their association.

Advantageous embodiments having useful and non-trivial refinements of the invention are described below.

BRIEF FIGURE DESCRIPTION

Further details and advantageous refinements of the invention are evident from the exemplifying embodiments, in no way to be understood as a limitation of the invention, that are described below and depicted in the drawings.

FIG. 1 is a frontal view of a fan arrangement;

FIG. 2 is a longitudinal section along a section line II-II showing the fan arrangement according to FIG. 1, having a first axial fan, a second axial fan, and a guide apparatus positioned between the first axial fan and the second axial fan;

FIG. 3 is a longitudinal section along a section line showing the fan arrangement according to FIG. 1, having the first axial fan, the second axial fan, and the guide apparatus positioned between the first axial fan and the second axial fan;

FIG. 4 is a rear view of the fan arrangement according to FIG. 1;

FIG. 5 is a perspective view of the fan arrangement according to FIG. 1, looking in the direction of a front view;

FIG. 6 is a side view showing a first fan housing of the first axial fan, a second fan housing of the second axial fan, and a guide apparatus housing of the guide apparatus;

FIG. 7 is a front view of the guide apparatus according to FIG. 1;

FIG. 8 is a longitudinal section along the section line VIII-VIII showing the guidance apparatus according to FIG. 7;

FIG. 9 is a perspective view of the guide apparatus according to FIG. 7;

FIG. 10 is a side view of the guide apparatus housing of the guide apparatus according to FIG. 7;

FIG. 11 is a rear view of the guide apparatus according to FIG. 1; and

FIG. 12 shows a fan arrangement having four fans connected to one another.

DETAILED DESCRIPTION

FIG. 1, FIG. 2, and FIG. 3 show a fan arrangement 10. Fan arrangement 10 comprises a first axial fan 20, a second axial fan 40, and a guide apparatus 60 that is arranged between first axial fan 20 and second axial fan 40. Fan arrangement 10 is flowthrough-capable. When fan arrangement 10 is operating, a fluid is delivered from an entrance surface 11 of fan arrangement 10 to an exit surface 12 of fan arrangement 10. A fluid delivery direction of fan arrangement 10 that is depicted is characterized by a directional arrow 100. The fluid can be, for example, a gas such as air or pure nitrogen, or a liquid, or also an aerosol such as mist or smoke.

A first electric motor 21 of first axial fan 20 and a second electric motor 41 of second axial fan 40 are respectively implemented in the form of an external-rotor motor. First electric motor 21 comprises a first external rotor 22 having a first shaft 29, having a first fan wheel 24, and having a first plurality of fan blades 25 attached to first fan wheel 24. A first internal stator 23 of first electric motor 20 is implemented to be at least partly surrounded by first external rotor 22. A first base part 26 of first electric motor 21 is connected to first internal stator 23. This first base part 26 serves to position first internal stator 23 in first electric motor 21, and to position a first bearing arrangement 28 for journaling of first shaft 29. First electric motor 21 is received in a first fan housing 27, implemented to radially enclose first electric motor 21 at least partly, of first axial fan 20. When first axial fan 20 is operating, first external rotor 22 rotates in a first rotation direction 31 around a first rotation axis 30 defined with the aid of first shaft 29.

Implemented between first fan housing 27 and first fan wheel 24 is a flowthrough-capable annular first conduit 32 through which the fluid can flow. When first axial fan 20 is operating, this fluid is delivered with the aid of the first plurality of fan blades 25 from a first entrance opening 33 of first conduit 32, which opening corresponds in this exemplifying embodiment to entrance surface 11, to a first exit opening 34 of first conduit 32. The fluid is preferably a gas, in particular air or another gas to be delivered.

In this exemplifying embodiment, second electric motor 41 is implemented to be identical in design to first electric motor 21. Identical design is not, however, an obligatory requirement for fan arrangement 10. The two electric motors can be configured differently in terms of, for example with respect to, their size or their output.

Second electric motor 41, which is positioned in a second fan housing 47, implemented to radially surround second electric motor 41 at least partly, of second axial fan 40, thus comprises a second external rotor 42 having a second shaft 49, having a second fan wheel 44, and having a second plurality, attached to second fan wheel 44, of fan blades 45. A second internal stator 43 of second electric motor 40 is implemented to be surrounded at least partly by second external rotor 42. A second base part 46 of second electric motor 41 is connected to second internal stator 43, second base part 46 serving to position second internal stator 43 in second electric motor 41 and to position a second bearing arrangement 48 for journaling second shaft 49. When second axial fan 40 is operating, second external rotor 42 rotates in a second rotation direction 51 around a second rotation axis 50 defined with the aid of second shaft 49.

Implemented between second fan housing 47 and second fan wheel 44 is a flowthrough-capable annular second conduit 52 through which the fluid can flow. When second axial fan 40 is operating, the fluid is delivered with the aid of the second plurality of fan blades 45 via a second entrance opening 53 of second conduit 52 to a second exit opening 54 of second conduit 52, second exit opening 54 corresponding to exit surface 12.

Guide apparatus 60, which is positioned between first axial fan 20 and second axial fan 40, comprises a guide apparatus housing 61 and a guide apparatus inner part 63 connected to guide apparatus housing 61 with the aid of webs 62. Guide apparatus housing 61 defines, together with guide apparatus inner part 63, a flowthrough-capable annular third conduit 64, annular third conduit 64 comprising a third entrance opening 65 and a third exit opening 66.

Webs 62 are positioned on a lateral surface 631 of guide apparatus inner part 63, lateral surface 631 being implemented to face toward guide apparatus housing 61 (see FIG. 3).

In this exemplifying embodiment, webs 52 are implemented in the form of guide vanes so that a conditioning of the fluid, i.e. a modification of flow parameters such as direction and swirl, is achievable. Guide vanes 62 are to be configured in terms of their radial and axial dimension in a manner adapted to a functionality of fan arrangement 10. In this exemplifying embodiment guide vanes 62 are implemented to straighten the fluid in air conduit 13.

In a further exemplifying embodiment, not depicted in greater detail, a first number of webs 62 are implemented in the form of rods having a circular cross section, and a second number of webs 62 are configured in the shape of guide vanes, the first number of webs 62 and the second number of webs 62 being fixedly connected both to guide apparatus inner part 63 and to guide apparatus housing 61. The second number of webs 62 could also be fixedly connected exclusively to guide apparatus inner part 63 or exclusively to guide apparatus housing 61.

In a further exemplifying embodiment, not depicted further, webs 62, implemented in the form of guide vanes, are implemented movably, in order to enable a change in flow conditioning as required, for example in the form of a controllable tilting motion of webs 62 around a radially extending axis.

When fan arrangement 10 is operating, the fluid is drawn into first conduit 32 via entrance surface 11 with the aid of the first plurality of fan blades 25, and delivered via third conduit 64 with the aid of the second plurality of fan blades 45 via second conduit 52 to exit surface 12, where the fluid can emerge in correspondingly conditioned fashion from fan arrangement 10. In other words, first conduit 32, second conduit 52, and third conduit 64 are respectively connected via first exit opening 34 and third entrance opening 65 and via third exit opening 66 and second entrance opening 53, forming a flowthrough-capable air conduit 13 of fan arrangement 10;

first rotation axis 30 and second rotation axis 50 are preferably implemented coaxially with a longitudinal axis 67 of guide apparatus 60.

First axial fan 20, second axial fan 40, and guide apparatus 60 could also be implemented in angled fashion with respect to one another. In other words, this means that first rotation axis 30, second rotation axis 50, and longitudinal axis 67 are arranged with respect one another to form angles that are different from an angle of 0° (or, equivalently, 180°).

In the exemplifying embodiment of fan arrangement 10 as depicted, first axial fan 20 and second axial fan 40 are implemented identically in terms of design and rotation. This is not obligatorily necessary, however. It is thus likewise possible, depending on the blade geometry, for first rotation direction 31 to be oriented oppositely to second rotation direction 51.

Guide apparatus inner part 63 is implemented for bracing reception of first axial fan 20 and of axial fan 40 respectively in a first portion 68 of guide apparatus inner part 63 and in a second portion 69 of guide apparatus inner part 63 (see FIG. 8), guide apparatus inner part 63 being immovably connected to first base part 26 and to second base part 46 for bracing reception. First internal stator 23 and second internal stator 43 are attached respectively to first base part 26 and to second base part 46, so that an indirect attachment of guide apparatus inner part 63 to first internal stator 23 and to second internal stator 43 is configured.

Guide apparatus inner part 63 is implemented in tubular fashion in order to receive first axial fan 20 and second axial fan 40, and to form the air conduit. Said inner part comprises a first inner lateral surface 70 to which is preferably attached a disk-like partition 71 whose axis 72 is implemented coaxially with longitudinal axis 67. Partition 71 forms a disk-shaped region of guide apparatus inner part 63 and serves as an axial stop for first base part 26 and/or second base part 46.

First base part 26 comprises a first bearing tube 35 to whose first outer surface 36 first internal stator 23 is preferably attached. First bearing arrangement 28 is preferably fastened on a first inner surface 37 of bearing tube 35.

Second base part 46 is configured correspondingly to first base part 26. It comprises a second bearing tube 55 having a second outer surface 56 and a second inner surface 57. Second internal stator 43 is attached to second outer surface 56, and second bearing arrangement 48 to second inner surface 57.

A second base part cover 59, shaped in the manner of a disk, of second base part 46 is positioned in a second bearing tube end region 58, positioned to face toward second portion 69, of second bearing tube 55; base part cover 59 can also be referred to as base part bottom 59. Second base part cover 59 serves at its second outer periphery 591 for radial abutment against inner lateral surface 70. The term “cover” does not imply that the part must be arranged at the bottom or top. At its second cover surface 592 positioned to face toward partition 71, it serves as an axial abutment against partition 71, so that second base part 46, and thus second axial fan 40, are received axially immovably in fan arrangement 10.

First bearing tube 35 comprises in its first bearing tube end region 38 a first base part cover 39, shaped in the manner of a disk, of first base part 26; base part cover 39 can also be referred to as a “base part bottom.” Like second base part cover 59, first base part cover 39 serves at its first outer periphery 391 for radial abutment against inner lateral surface 70. Its first cover surface 392, positioned to face toward partition 71, abuts axially against partition 71 so that first base part 46, and thus first axial fan 20, are received axially immovably in fan arrangement 10.

In the exemplifying embodiment depicted, partition 71 comprises, at its end implemented to face away from inner lateral surface 70, a tubular portion 73 that serves for axial abutment of second cover surface 592 against its first base surface 74 facing toward first base part cover 39. The advantage of this tubular portion 73 is that,

in addition to the axial abutment of second cover surface 592, a sufficiently stable radial abutment of first bearing tube end region 38 and of second bearing tube end region 58 is achieved. Partition 71 is configured here to have a wall thickness D of partition 71 which is smaller as compared with a length L of tubular portion 73. In other words, the use of tubular portion 73 leads to a reduction in wall thickness D, with the prerequisite that a sufficiently stable radial abutment of first bearing tube end region 38 and of second bearing tube end region 58 is to be brought about. This also simplifies production using the plastic injection-molding method, since greatly different thicknesses are critical because of the difference in expansion.

Tubular portion 73 can alternatively point toward first cover surface 392.

In order to bring about stable radial abutment, it is advantageous that first bearing tube 35 in its first bearing tube end region 38, and second bearing tube 55 in its second bearing tube end region 58, respectively abut radially against tubular portion 73 over a sufficient longitudinal extent E. If partition 71 did not comprise tubular portion 73, this would mean either that wall thickness D corresponds to length L, or that the radial abutment of first bearing tube end region 38 and of second bearing tube end region 58 would be less stable, since longitudinal extent E would be small.

The advantage of tubular portion 73 is thus to be regarded as the fact that a wall thickness D, which in addition to a reduction in material cost brings about improved elasticity of the bracing function of guide apparatus inner part 63, can be used; this avoids an increase in weight.

FIG. 3 is a longitudinal section along a section line of FIG. 1, showing fan arrangement 10. First fan housing 27 surrounds a first housing body 271 that is configured in the manner of a hollow cylinder. First housing body 271 is furthermore preferably conically shaped in the region of first entrance opening 33, so that first housing body 271 is configured in the manner of a Venturi tube. This results in an increase in a flow velocity of the fluid at least in first conduit 32. A straight termination of the air conduit can also be selected, however. The same applies to the oppositely located side.

In the region of first entrance opening 33, first fan housing 27 comprises a first entrance flange 272 that can be implemented in disk-like fashion, in particular to have a rectangular, preferably a square first cross-sectional surface 274. Positioned at first entrance flange 272 are four first flange openings 275, extending with a uniform spacing from one another entirely over a first flange wall thickness FD1 of first entrance flange 272, which are implemented to receive a connecting or attaching element, for example a screw or a bolt.

A first exit flange 273 of first fan housing 27 is configured in the region of first exit opening 34. Like first entrance flange 272, it is likewise implemented in disk-like fashion, in particular to have a rectangular, preferably a square second cross-sectional surface 276. In this exemplifying embodiment, first cross-sectional surface 274 corresponds to second cross-sectional surface 276. This is not obligatorily necessary. Second cross-sectional surface 276 could also have a conformation that differs from first cross-sectional surface 274.

First exit flange 273 also comprises four second flange openings 277, positioned with a uniform spacing from one another and extending preferably entirely over a second flange wall thickness FD2 of first exit flange 273, which are implemented to receive a connecting or attaching element, for example a screw or a bolt 278.

First fan housing 27 is connected to guide apparatus housing 61 in the region of first exit opening 34 and of third entrance opening 65, or is attached to guide apparatus housing 61; in other words,

no webs that extend directly between the base parts and the respective fan housing are necessary. In order to receive the connecting or attaching means, guide apparatus housing 61 comprises four (or three or five) receiving elements 612 implemented in the manner of hollow cylinders, which are each connected, for example with the aid of a fastening web 613 (see FIG. 7), to an annularly implemented third housing body 611 of guide apparatus housing 61. The four receiving elements 612 are positioned respectively oppositely from the four second flange openings 277, in such a way that an element axis EA1 of connecting or attaching means 278 exists coaxially with a receiving element axis AA of receiving element 612 and coaxially with a first flange opening axis FA1 of second flange opening 277.

In the region of third exit opening 66, guide apparatus housing 61 is attached to second fan housing 47 at the latter's second entrance flange 472. Second entrance flange 472 is implemented in the region of second entrance opening 53 in disk-like fashion,

in particular to have a rectangular, preferably a square third cross-sectional surface 474. Second entrance flange 472 comprises four third flange openings 475, positioned with a uniform spacing from one another and extending preferably entirely over a third flange wall thickness FD3 of second entrance flange 472, which are implemented to receive an associated connecting or attaching element 478. The four third flange openings 475 are positioned respectively oppositely from the four receiving elements 612, element axis EA2 of the connecting or attaching means preferably existing coaxially with receiving element axis AA and coaxially with a second flange opening axis FA2 of third flange opening 475.

In the present exemplifying embodiment, second flange opening axis FA2 corresponds to first flange opening axis FA1.

A second exit flange 473 of second fan housing 47 is configured in the region of second exit opening 54. Like second entrance flange 472, it is likewise implemented in disk-like fashion, in particular to have a rectangular, preferably a square fourth cross-sectional surface 476. In this exemplifying embodiment, third cross-sectional surface 474 corresponds to fourth cross-sectional surface 476.

Fourth cross-sectional surface 476 could also have a conformation differing from third cross-sectional surface 474.

Second exit flange 473 (see FIG. 4) also comprises four fourth flange openings 477, positioned with a uniform spacing from one another and extending preferably entirely over a fourth flange wall thickness FD3 of second exit flange 473, which are implemented to receive a connecting or attaching element.

FIG. 5 is a perspective view of fan arrangement 10 looking toward the front view, thus looking toward entrance surface 11 or first entrance flange 272. As is also clearly apparent from FIG. 6, support struts 80 are preferably positioned between first entrance flange 272 and first exit flange 273, and between second entrance flange 472 and second exit flange 473.

These support struts 80 serve to stabilize fan arrangement 10. Fan arrangement 10 comprises electric motors (first electric motor 21 and second electric motor 41) that rotate during operation. In other words, first fan housing 27 and second fan housing 47 are already exposed to motions in the form of rotational motions simply as a result of the operation respectively of first electric motor 21 and of second electric motor 41. These motions could result in twisting of first fan housing 27 and of second fan housing 47. To avoid such twisting, support struts 80 are implemented between first entrance flange 272 and first exit flange 273, and between second entrance flange 472 and second exit flange 473. Support struts 80 thus serve on the one hand for lightweight construction of fan arrangement 10, and on the other hand to maintain elasticity of the overall fan arrangement 10, which because of support struts 80 can maintain its stability even in a context of externally acting vibratory excitations.

FIG. 7 to FIG. 11 depict guide apparatus 60 in a front view looking toward third entrance opening 65, in a longitudinal section along a section line in a perspective view with a viewing direction proceeding from third entrance opening 65, in a side view, and in a rear view.

FIG. 12 shows a further embodiment of fan arrangement 10 in which four fans 20, 40, 40′, 40″ are connected serially to one another in order to achieve a greater output for fan arrangement 10. The depiction corresponds to a section that from top to center corresponds to the section line II-II of FIG. 1, and from the center diagonally downward to the right corresponds to the section line of

FIG. 1.

First fan 20 is connected to second fan 40 via guide apparatus 60, as in the other exemplifying embodiments; second fan 40 is connected to third fan 40′ via guide apparatus 60′; and third fan 40′ is connected to fourth fan 40″ via guide apparatus 60″.

The annular air conduit 13 extends in an axial direction through the entire fan arrangement 10; in order to avoid air noise, the outer side of air conduit 13 preferably has no enlargement at least in the inner region. Alternatively to FIG. 12, an enlargement of air conduit 13 can be provided at the axial ends.

Fans 20 and 40 on the one hand, and fans 40′ and 40″ on the other hand, are respectively connected to guide apparatus 60 and 60″ externally at the housing and internally at the flange; fans 40 and 40′, on the other hand, are connected only externally at the housing, since internally the fan rotor is respectively associated with flange 60′. In a fan arrangement 10 having three fans, however, the appropriate fan 40″ could be installed directly on guide apparatus 60′, so that only one fan would be attached to guide apparatus 60′.

Fan 40′ (optionally with fan 40″) can alternatively also be connected to fan 20.

According to a preferred embodiment, any plurality of fans 20, 40 can thus be coupled to one another by way of guide apparatuses 60.

It is very advantageous that guide apparatus 60, 60′, 60″ can be used in any way (in consideration of the rotation direction of the fans) in order to connect the individual fans. A modular configuration is thereby enabled.

Many variants and modifications are of course possible in the context of the present invention. 

1. A fan arrangement comprising a first axial fan (20), a second axial fan (40), and a guide apparatus (60), the first axial fan (20) including: a first electric motor (21) having a first external rotor (22) and a first internal stator (23); a first fan wheel (24) connected to the first external rotor (22) and having a first plurality of fan blades (25); a first base part (26) connected to the first internal stator (23); and a first fan housing (27), which first fan housing (27) at least partly surrounds the first electric motor (21); and the second axial fan (40) including: a second electric motor (41) having a second external rotor (42) and a second internal stator (43); a second fan wheel (44) connected to the second external rotor (42) and having a second plurality of fan blades (45); a second base part (46) connected to the second internal stator (43); and a second fan housing (47), which second fan housing (47) at least partly surrounds the second electric motor (41); the first fan housing (27) defining, together with the first fan wheel (24), an annular first conduit (32) through which a fluid is deliverable during operation by rotation of the first fan wheel (24) around a first rotation axis (30) of the first external rotor (22); the second fan housing (47) defining, together with the second fan wheel (44), an annular second conduit (52) through which the fluid is deliverable during operation by rotation of the second fan wheel (44) around a second rotation axis (50) of the second external rotor (42); and the guide apparatus (60) including a guide apparatus housing (61) and a guide apparatus inner part (63) connected to the guide apparatus housing (61) with the aid of webs (62), which guide apparatus housing (61) defines, together with the guide apparatus inner part (63), an annular third conduit (64) through which the fluid is deliverable; the first base part (26) being attached to a first portion (68) of the guide apparatus inner part (63) and the second base part (46) being attached to a second portion (69) of the guide apparatus inner part (63); and the first axial fan (20), the second axial fan (40), and the guide apparatus (60) being connected to one another in such a way that the first annular conduit (32), the second annular conduit (52), and the third annular conduit (64) collectively form a flowthrough-capable air conduit (13) of the fan arrangement (10).
 2. The fan arrangement according to claim 1, wherein a longitudinal axis (67) of the guide apparatus (60), the first rotation axis (30), and the second rotation axis (50) are implemented coaxially.
 3. The fan arrangement according to claim 1, wherein the guide apparatus inner part (63) comprises guide vanes on a lateral surface (631), configured to face toward the guide apparatus housing (61).
 4. The fan arrangement according to claim 1, wherein the webs (62) are implemented in the form of guide vanes.
 5. The fan arrangement according to claim 1, wherein, the guide apparatus (60) is rigidly coupled to at least one of the first internal stator (23) and the second internal stator (43).
 6. The fan arrangement according to claim 1, wherein, the first base part (26) is configured to position the first internal stator (23) and a first bearing arrangement (28) with respect to a first central shaft (29) of the first electric motor (21), and the second base part (46) is configured to position the second internal stator (43) and a second bearing arrangement (48) with respect to a second central shaft (49) of the second electric motor (41).
 7. The fan arrangement according to claim 6, wherein, the first base part (26) abuts in an axial direction against the first portion (68), and the second base part (46) abuts in an axial direction against the second portion (69).
 8. The fan arrangement according to claim 6, wherein, the first base part (26) abuts in a radial direction against the first portion (68), and/u, the second base part (46) abuts in a radial direction against the second portion (69).
 9. The fan arrangement according to claim 1, wherein, the guide apparatus inner part (63) is formed with a disk-shaped region (71) that serves as an axial stop at least for the first base part (26).
 10. The fan arrangement according to claim 9, wherein the disk-shaped region (71) is integrally formed with a tubular portion (73).
 11. The fan arrangement according to claim 1, wherein at least one of the first fan housing (27) and the second fan housing (47) is immovably connected to the guide apparatus housing (61).
 12. The fan arrangement according to claim 1, wherein at least one of the first base part (26) and the second base part (46) is connected to a respective adjacent portion (68,69) via a press fit.
 13. The fan arrangement according to claim 1, wherein the guide vanes (62) are so shaped that, during fan operation, they straighten the fluid in the air conduit (13).
 14. The fan arrangement according to claim 1, wherein, the air conduit (13) is formed with a Venturi tube constriction.
 15. The fan arrangement according to claim 1, wherein, during operation, the first axial fan (20) has a first rotation direction (31) and the second axial fan (40) has a second rotation direction (51), directed oppositely to the first rotation direction (31).
 16. The fan arrangement according to claim 1, further comprising a third axial fan (40′, 40″), which is connected via a further guide apparatus (60′) to one of the first fan (20) and the second fan (40).
 17. The fan arrangement according to claim 16, further comprising a fourth axial fan (40″), which is connected via a further guide apparatus (60″) to the third axial fan (40′).
 18. The fan arrangement according to claim 2, wherein the guide apparatus inner part (63) comprises guide vanes on a lateral surface (631), configured to face toward the guide apparatus housing (61). 